The French president told Theresa May her opening gambit in Florence “isn’t halfway there” and ordered the PM to make a “substantial financial effort” if she wants to break the divorce talks deadlock.

He also accused Mrs May of “bluffing” over her threats to prepare Britain for a no-deal exit from the bloc, saying she had never reaised the possibility of the talks breaking down during meetings with EU leaders.

Meanwhile, the PM was unsurprisingly unenthusiastic when asked for a number the UK is prepared to stump up, simply saying officials will be going “line by line” through Britain’s commitments.

Mr Macron told reporters at a press conference following the latest EU Council summit in Brussels that “a lot is in the hands of Theresa May” and that only a better cash offer from the UK will move the negotiations forwards.

He said: “If, as Prime Minister May said in Florence, we want to make sure that no-one will have to pay more or receive less, and if we want to make sure the UK will comply with all its commitments made as a member of the EU, I would say we are far from having reached the necessary financial commitments before we can open phase two.

“We are far from where we should be in this respect. I can only underline how much work needs to be done.”

His remarks came after Angela Merkel admitted the Brexit bill is now the “dominating issue” in the Brexit talks, with EU leaders increasingly turning their focus towards securing an agreement on money.

The German chancellor said: “Theresa May has been talking to a number of EU member states in the run up to this meeting and we’ve been quite clear on why we think sufficient progress hasn’t been made in relation to the financial commitments. Therefore, it’s quite clear what needs to be furnished further.”

Britain’s impending exit will create a cash crisis for the European project, which is set to lose its second biggest net contributor at a time when few other countries can afford to take up the slack.

EU budget chief Gunther Oettinger has estimated the bloc needs to make up around £10 billion a year just due to the UK leaving alone, saying that half of this should come from cuts and the other half from new contributions.

However, few member states aside from Germany can currently afford to pump in the kind of cash required to plug the gap, whilst cutback are a political nightmare given they have to be agreed unanimously by the 27.

On top of that some of the bloc’s wealthier nations, like Austria, the Netherlands and Switzerland, have all signalled strong opposition to paying a penny more into the budget after Brexit.

As a result, the EU is determined to get as big a settlement out of Britain as possible to it can kick the politically explosive issue of payments into the long grass until at least the mid 2020s.

EU parliament president Antonio Tajani has recently put the amount required by the bloc at somewhere between £40-60bn, whilst some EU sources have suggested the demand could rise to as much as £90bn.

Tory MEP Syed Kamall told express.co.uk: “If you look at the negotiations and take a step back and say what are the strengths and weaknesses of both sides, the EU’s biggest weakness is clearly the money.

“Austria, Denmark and Sweden saying we are not going to pay a penny more when the UK leaves, countries such as Poland saying we will not receive a penny less. So effectively Barnier has to go and get as much money as possible from the UK.”